From 540a73bdd3b4b7a43ed86dd9077fc2f3a15f8b65 Mon Sep 17 00:00:00 2001
From: Erik Pilkington <erik.pilkington@gmail.com>
Date: Thu, 21 Jul 2016 22:31:40 +0000
Subject: [PATCH] [CodeGen] Fix a crash when constant folding switch statement
Differential revision: https://reviews.llvm.org/D22542
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@276350 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/CodeGen/CGStmt.cpp | 8 ++++++++
test/CodeGenCXX/switch-case-folding-2.cpp | 9 +++++++++
2 files changed, 17 insertions(+)
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index a7fa60f73ad..31f19829d92 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -1264,6 +1264,14 @@ void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) {
}
void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S) {
+ // If there is no enclosing switch instance that we're aware of, then this
+ // default statement can be elided. This situation only happens when we've
+ // constant-folded the switch.
+ if (!SwitchInsn) {
+ EmitStmt(S.getSubStmt());
+ return;
+ }
+
llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest();
assert(DefaultBlock->empty() &&
"EmitDefaultStmt: Default block already defined?");
diff --git a/test/CodeGenCXX/switch-case-folding-2.cpp b/test/CodeGenCXX/switch-case-folding-2.cpp
index b0bbf3282ac..558ca3c87d9 100644
--- a/test/CodeGenCXX/switch-case-folding-2.cpp
+++ b/test/CodeGenCXX/switch-case-folding-2.cpp
@@ -18,4 +18,13 @@ int main(void) {
return test(5);
}
+void other_test() {
+ switch(0) {
+ case 0:
+ do {
+ default:;
+ } while(0);
+ }
+}
+
// CHECK: call i32 (i8*, ...) @_Z6printfPKcz
--
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